The present invention comprises a new and distinct cultivar of calla lily, botanically known as Zantedeschia sprengeri and hereinafter referred to by the cultivar name ‘Snow Storm’.
‘Snow Storm’ is a product of a planned breeding program, which had the objective of creating Zantedeschia hybrids for pot flower production in a wide range of colors with a large, classic flower shape. The breeding program began in 1989, and the new cultivar is a seedling selected from the crossing of a Zantedeschia sprengeri seedling referred to as Z041613-632 (female parent, unpatented) with a Zantedeschia sprengeri seedling referred to as Z051287 (male parent, unpatented). ‘Snow Storm’ was selected in 2009 by the inventor in 't Zand, The Netherlands as one flowering plant within the progeny of the stated cross.
The first act of asexual reproduction of ‘Summer Snow’ by tissue culture was performed by the inventor in September of 2009 in 't Zand, The Netherlands. Subsequent asexual reproductions by tissue culture at the same location have demonstrated that the combination of characteristics as herein disclosed for the new cultivar are retained and reproduced true to type through successive generations of asexual reproduction.
The following observations, measurements and comparisons describe plants grown in a 14 cm pot at 12-14 weeks after planting in 't Zand, The Netherlands under greenhouse conditions, which approximate those generally used in horticultural practice. Color references are made to The 2001 R.H.S. Colour Chart of The Royal Horticulture Society of London, except where general color terms of ordinary significance are used.
The present invention has not been evaluated under all possible environmental conditions. The phenotype may vary with variations in environment without a change in the genotype of the plant.
The following traits have been repeatedly observed and determined to be basic characteristics of ‘Snow Storm’ which, in combination, distinguish this calla lily as a new and distinct cultivar:                1. White-colored spathe without a pink blush;        2. Green-colored leaves with numerous white linear markings; and        3. High inflorescence production.        
Further, when compared to calla lily plant named ‘Chrystal Blush’ (unpatented), ‘Chrystal Blush’ has a white spathe color with a blush (R.H.S. values unknown), and such blush is absent with ‘Snow Storm’. Additionally, when compared to calla lily plant named ‘Captain Ventura’ (U.S. Plant Pat. No. 21,245), the upper surface spathe color of ‘Captain Ventura’ varies between Yellow-Green Group RHS 150D and Green-White Group RHS 157C, whereas the upper surface spathe color of ‘Snow Storm’ varies between White Group RHS 155A and 155D.
Table 1 provides similarities and differences of ‘Snow Storm’ to its parents, Zantedeschia sprengeri seedlings Z041613-632 and Z051287.
TABLE 1‘Snow Storm’SimilaritiesDifferencesZ041613-632Spathe shapeSpathe color (BetweenYellow-White Group RHS158D and 159D)Spathe without pink blushPlant height (10-50 cm)Z051287Number of inflorescencesSpathe shape (Funnel)Spathe color (BetweenGreen-White Group RES157D and White GroupRHS N155A)